Selective positioning mechanisms



Aug. 25, 1959 c. A. HENN-COLLINS 2,901,727

/ SELECTIVE POSITIONING MECHANISMS Filed April 8, 1955 United States Patent 2,901,727 SELECTI VE POSITIONING MECHANISMS Christopher Arthur Henn-Collins, London, England Application April 8, 1955, Serial No. 500,261

Claims priority, application Great Britain April 9, 1954 7 Claims. (Cl. 340-324) This invention relates to selective positioning mechanisms intended to bring a controlled member into a desired position out of a number of possible positions under the control of appropriate code impulses or signals. The invention can be applied with particular advantage to type printing telegraph apparatus where it is required to convert code signals to positional data for printing purposes. However, the invention is not restricted to such use but can be employed for remote positioning purposes in other apparatus such as computers, particularly of the analogue type, calculating machines, and the like.

It is an object of the invention to provide an improved mechanism of the above character which is relatively simple in structure and satisfactory in operation and which is particularly adapted for use in conjunction with binary code transmission means. Another object is to provide an improved mechanism of the above character for positioning the type wheel or sector of the type printing telegraph apparatus whereby a simplification of the usually employed mechanism is achieved.

According to the invention the position of a controlled member is determined by two or more movable members having predeterminable ranges of motion serially connected to the controlled member by independently controllable power means for effecting relative movement between the members so that a final motion is obtained which is the algebraic sum of the movement of the individual members. By providing a sufiicient number of such members the individual permitted movements of which are suitably related, any desired number of final controlled positions can be obtained. The power means which constitute the driving or motion transmitting connections may be actuated by any desired medium but preferably an electrical or electromagnetic drive is employed comprising pairs of magnetic poles suitably arranged with at least one pair of poles constituted by an electromagnet in which current can be reversed to efiiect the desired relative motion.

The movable members may be arranged for either recr tilinear or angular motion, or a series of members may comprise both such motions.

The limit positions of individual movable members may be determined by the magnetic poles, or alternatively stop means may be provided for this purpose, and such stop means may be adjustable or variable if desired.

It is a further feature of the invention that each of the movable members is retained in the position to which it has been moved, and in the arrangement referred to above this is ensured by the magnetic attraction between adjacent poles when the movable member occupies either of its limit positions.

For a more complete understanding of the invention reference should be had to the accompanying drawing in which:

Figure 1 is a perspective view of one form of apparatus according to the invention;

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Fig. 2 is a sectional view of another form of apparatus according to the invention; and

Fig. 3 is a fragmentary view of a modified form of apparatus shown in Fig. 2.

In carrying the invention into effect according to one convenient mode, a controlled rotatable member has its angular motion determined by angularly movable and coaxially arranged members which are connected by electromagnetic drive transmitting means.

Referring to Fig. 1, a fixed stator ring 10 has two pairs of magnetic poles 11 and 12 arranged within it at apart. A transversely disposed electromagnetic armature 13 is rotatably mounted within the stator 11 and suitable flexible connections 14 or other arrangements are provided whereby a current can be passed in either direction as desired through the winding 15. The stator poles may be provided by permanent magnets of arcuate form or otherwise as desired. The armature is connected to a ring 16 which rotates with it, and fixed to the interior of this ring is a pair of magnetic poles 17 and 18 similar to those of the stator but arranged at 45 apart. A second armature 19 similar to the first is rotatable inside the ring and connected to a driving element or shaft 21. A winding 22 is disposed around armature 19 and flexible conductors 23 or the like may supply current to such winding. The shaft 21 is connected to a printing Wheel or the like 24.

It will be seen that with current applied in an appropriate direction to both armatures the driving element will occupy a zero position as shown. If the current in the first armature winding 15 is reversed, the driving element 21 will make a quarter turn, and if the current in the second armature winding 22 alone is reversed, the driving element will make a 45 turn. Thus by appropriately energizing the two armatures there can be afforded a zero position and three rotational positions of 45 90 or from the zero. Further elements may be included in the series if desired to provide additional angular positions.

In the described arrangement the limits of angular movement of the armatures are determined by the permanent magnet poles. If desired, however, these movements can be limited by stops to an angle less than the angle subtended by the opposite poles, and these stops can be adjustable or selectively variable. It is to be noted that in both arrangements the armatures will be held or retained in each of their limit positions by magnetic force even if the current in the armature winding is interrupted. Preferably the movable members are all of the same diameter for ease in manufacture.

In carrying the invention into efiect according to another mode involving rectilinear motion of the movable members reference is made to Fig. 2 wherein there is shown a fixed core 26 upon which is axially slidable an electromagnet 27 of sleeve form carrying a winding 28 coaxial with the core 26 and having flexible or other suitable electrical connections 29. The core 26 is provided with spaced shoulders 31 and 32 between which the sleeve magnet is slidable and these shoulders are oppositely magnetized, either by permanent magnets or by continuously energized windings. The arrangement is such that the sleeve magnet 27 will take up one or other of its two end positions according to the direction in which current is applied to its winding 28.

A second core member 33 is mounted for sliding motion coaxiall'y with the sleeve magnet 27 to which it is coupled in any suitable manner as on a shaft 34. This second core has magnetized shoulders 35 and 36 as described for the first core 26 and carries a second sleeve electromagnet 37 having a winding 38 to which current can be applied in either direction. The second sleeve magnet 37 can be connected to the member required to be positioned as by shaft 39. If the permissible travel of the sleeve magnet 27 on the first core 26 is assumed to be two steps, and the permissible travel of the second magnet 37 on its core is one step, there are afforded a zero and three unit positions. It will be evident that by providing a series with additional movable parts similar to those described any desired number of final positions can be determined.

Any tendency for the sleeve magnets of Fig. 2 to stick to the magnetic shoulders may be obviated by the constmction of Fig. 3 in which a sleeve magnet 41, in fragmentary form, is shown. Magnetic pole pieces 42 and 43 corresponding to the pole pieces of Fig. 2 are shown radially outward of the circumference of the sleeve magnet 41. The small gap 44 avoids metal-to-metal contact between the sleeve magnet and the pole pieces and possible sticking of these parts while permitting positive movement of the magnet.

The above mechanisms involving angular and rectilinear motions respectively can readily be combined if desired to position a drum or sector both rotationally and axially, such combination being particularly suitable for type printing telegraph apparatus, for example, or other apparatus where similar requirements are to be met.

By this invention there is provided a positioning mechanism which is particularly suitable for use in conjunction with binary code transmission means, and the controlling impulses or signals can be applied to the mechanism in any desired or known manner. It is an advantage of the arrangement that the signals can be applied in any desired order without affecting the final result. The invention is not restricted to the examples described, and it is to be noted that if the movements of the members are limited by stop means instead of by the conjunction of magnetic pole pairs, the construction of the main elements can be standardised. Also the limits of movement of each of the movable members may bear any desired fractional or other relation to afford a large number of selected final positions.

While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated by the appended claims to cover any such modifications as fall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. Aggregate motion positioning means comprising first permanent magnet means having fixed positioned north and south poles disposed in a predetermined manner, a first armature mounted for movement between said north and south poles, said first armature having a winding adapted to be energized with direct current for determining the position of said first armature in accordance with the polarity of such direct current, second permanent magnet means whose position is determined by said first armature, said second permanent magnet means having north and south poles disposed in a predetermined manner, and a second armature mounted for movement between the north and south poles of said second permanent magnet means, said second armature having a winding adapted to be energized with direct current for determining the position of said second armature in accordance with the polarity of such direct current.

2. Positioning means comprising a pair of magnetic members angularly disposed with respect to each other and having ends, a movable member having two rotative positions, one when disposed against one pair of diametrically opposed ends of said magnetic members and another when disposed against the other pair of diametrically opposed ends of said magnetic members, said mag- 4 nen'c members having an arcuate span determinative of the extent of rotative movements of said movable memher, and winding means on said movable member and adapted to be energized with direct current for determining the rotative position of said movable member in accordance with the polarity of such direct current.

3. Positioning means comprising permanent magnet means having north and south poles linearly disposed with respect to each other, a movable member having two linear positions, one when disposed against one of said north and south poles and another when disposed against the other of said north and south poles, said north and south poles having a linear span determinative of the extent of linear movement of said movable member, and winding means on said movable member and adapted to be energized with direct current for determining the linear position of said movable member in accordance with the polarity of such direct current.

4. Positioning means comprising permanent magnet means having north and south poles linearly disposed with respect to each other, a movable member having two linear positions, one when disposed adjacent to but displaced from the other of said north and south poles, and another when disposed adjacent to but displaced from the other of said north and south poles, said north and south poles having a linear span determinative of the extent of linear movement of said movable member, and winding means on said movable member and adapted to be energized with direct current for determining the linear position of said movable member in accordance with the polarity of such direct current.

5. Aggregate motion positioning means comprising a first member for assuming one of two predetermined positions, first electromagnetic means for producing a change in such position assumed by said first member, a second member movable independently of and controllable by said first member assuming one of two predetermined positions relative to said first member, and electromagnetic means for producing a change in such predetermined position assumed by said second member relative to said first member.

6. Aggregate motion positioning means comprising a first member for assuming one of two predetermined positions, first electromagnetic means for producing a change in such position assumed by said first member, a second member movable independently of and controllable by said first member assuming one of two predetermined positions relative to said first member, electromagnetic means for producing a change in such predetermined position assumed by said second member relative to said first member, and means for indicating the algebraic sum of changes in position of said first and said second members.

7. Aggregative positioning means comprising a first member for assuming one of two predetermined positions, first electromagnetic means responsive to a signal for regulating the position assumed by said first member, a second member movable both independently of and with said first member, and second electromagnetic means responsive to a signal for producing such independent movement of said second member relative to said first member.

References Cited in the file of this patent UNITED STATES PATENTS 1,222,431 McCarthy Apr. 10, 1917 1,636,050 Fottinger July 19, 1927 1,638,098 Rochette Aug. 19, 1927 2,719,290 Bland Sept. 27, 1955 

